X-ray detection device

ABSTRACT

An X-ray detection device includes a substrate, a first transistor disposed on the substrate and including a silicon semiconductor, a second transistor disposed on the substrate and including a metal oxide semiconductor, a sensor disposed on the first transistor and the second transistor and electrically connected to the first transistor and the second transistor, a first barrier layer disposed between the first transistor and the second transistor, and a second barrier layer disposed between the second transistor and the sensor. The X-ray detection device may further include a scintillator disposed on the sensor.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

The present disclosure is related to an X-ray detection device, and moreparticularly to an X-ray detection device including semiconductor layerswith different materials.

2. Description of the Prior Art

With the rapid development of technology, various imaging technologiesof visible light and invisible light are both widely used in daily life.For example, medical personnel often use X-ray sensors to obtain imagesfor medical behavior, or enterprises may use X-ray sensors to detect thequality of goods etc. A pixel array composed of transistors is oftenused as a main component of the conventional flat-type X-ray sensor.However, the semiconductor layers in the transistors may be affected byother subsequent processes or the characteristics of the films producedafterward, which will further affect the detection accuracy of the X-raysensor. Therefore, how to design the element structure to provide anX-ray sensor with better sensing effect is still an issue that needs tobe continuously studied in the industry.

SUMMARY OF THE DISCLOSURE

The present disclosure provides an X-ray detection device which has twotransistors and one sensor, and the X-ray detection device furtherincludes a first barrier layer and a second barrier layer. By disposingthe barrier layers, the quality of the semiconductor layers of thetransistors can be improved, and the electrical performance of thetransistors can also be raised, so as to improve the detection effectand accuracy of the X-ray detection device.

The X-ray detection device provided by the present disclosure includes asubstrate, a first transistor disposed on the substrate and including asilicon semiconductor, a second transistor disposed on the substrate andincluding a metal oxide semiconductor, a sensor disposed on the firsttransistor and the second transistor and electrically connected to thefirst transistor and the second transistor, a first barrier layerdisposed between the first transistor and the second transistor, and asecond barrier layer disposed between the second transistor and thesensor. The X-ray detection device may further include a scintillatordisposed on the sensor.

These and other objectives of the present disclosure will no doubtbecome obvious to those of ordinary skill in the art after reading thefollowing detailed description of the embodiment that is illustrated inthe various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial schematic diagram of the element arrangement of anelectronic device of the present disclosure.

FIG. 2 is a partial cross-sectional schematic diagram of an X-raydetection device according to a first embodiment of the presentdisclosure.

FIG. 3 is a partial cross-sectional schematic diagram of an X-raydetection device according to a second embodiment of the presentdisclosure.

FIG. 4 is a partial cross-sectional schematic diagram of an X-raydetection device according to a third embodiment of the presentdisclosure.

FIG. 5 is a partial cross-sectional schematic diagram of an X-raydetection device according to a fourth embodiment of the presentdisclosure.

FIG. 6 is a partial cross-sectional schematic diagram of an X-raydetection device according to a fifth embodiment of the presentdisclosure.

FIG. 7 is a partial cross-sectional schematic diagram of an X-raydetection device according to a sixth embodiment of the presentdisclosure.

FIG. 8 is a partial cross-sectional schematic diagram of an X-raydetection device according to a seventh embodiment of the presentdisclosure.

FIG. 9(A) is a partial cross-sectional diagram of an X-ray detectiondevice according to an eighth embodiment of the present disclosure.

FIG. 9(B) is an equivalent circuit diagram of one sensing pixel PX ofthe X-ray detection device shown in FIG. 9(A).

FIG. 10 is a schematic diagram of process flow of the fabrication of theX-ray detection device according to the present disclosure.

DETAILED DESCRIPTION

The present disclosure may be understood by reference to the followingdetailed description of embodiments, taken in conjunction with thedrawings as described below. It is noted that, for purposes ofillustrative clarity and being easily understood by the readers, variousdrawings of this disclosure show a portion of the device or structure,and certain elements in various drawings may not be drawn to scale. Inaddition, the number and dimension of each element shown in drawings areonly illustrative and are not intended to limit the scope of the presentdisclosure.

Certain terms are used throughout the description and following claimsof the present disclosure for referring to particular components. As oneskilled in the art will understand, electronic equipment manufacturersmay refer to a component by different names. This document does notintend to distinguish between components that differ in name but notfunction. In the following description and in the claims, the terms“include”, “comprise” and “have” are used in an open-ended fashion, andthus should be interpreted to mean “include, but not limited to”. Whenthe terms “comprising”, “including” and/or “having” are used in thisspecification, they designate the presence of the stated feature,region, step, operation and/or element, but do not exclude the presenceor addition of one or more other features, regions, steps, operations,elements and/or combinations thereof.

The ordinal terms used in the specification and claims, such as “first”,“second”, etc., are used for indicating elements in the claims. They donot imply and represent any sequential order in the claims, nor does itrepresent the order of a certain claimed element with respect to anotherclaimed element, or the order of the manufacturing method. The use ofthese ordinal terms is only to clearly distinguish a claimed elementwith a certain name from another claimed element with the same name.

The directional terms mentioned in the embodiments, such as “up”,“down”, “left”, “right”, “front”, “back”, etc., are only directionsreferring to the drawings. Therefore, the directional terms used are forillustration, not for limitation of the present disclosure. It should beunderstood that the element particularly described or labeled in thedrawings may be existed as various forms known by those skilled in theart. In addition, when an element or layer is referred to as being on orconnected to another element or layer, it should be understood that theelement or layer is directly on or connected to another element or onanother layer, or there may be other elements or layers between the two(indirectly circumstance). However, on the contrary, when the element orlayer is referred to being “directly on” or “directly connected to”another element or layer, it should be understood that no interveningelements or layers are existed therebetween. When the specificationdescribes that a first device of the circuit is electrically connectedto a second device, it refers to that the first device may beelectrically connected to the second device directly, or the firstdevice may be electrically connected to the second device indirectly.When the first device is electrically connected to the second devicedirectly, the first device and the second device are connected throughonly conductive lines or passive elements (such as resistance andcapacitor) and no other electric devices connect between the firstdevice and the second device.

When the term “on” or “above” is mentioned, it includes the situation ofdirect contact or the situation that one or more other elements areintervened between two mentioned-elements, and in the latter situation,the two mentioned-elements may not be in contact with each otherdirectly.

In the present disclosure, the thickness, the length, and the width maybe measured by an optical microscopy (OM), and the thickness and thelength may be measured through a cross-sectional image of a scanningelectron microscope (SEM), but not limited thereto. In addition, someerrors or inaccuracy may exist between any two values or directions usedfor comparison.

In the specification, the terms “about”, “substantially”, “around”, and“approximately” generally mean within 10% of a given value or range, ormean within 5%, 3%, 2%, 1%, or 0.5% of a given value or range. A givenquantity herein is an approximate quantity, that is, even in thesituation of an absence of a specific description of “about”,“substantially”, “around”, or “approximately”, it may still imply themeaning of “about”, “substantially”, “around”, or “approximately”.

It should be noted that, from the described embodiments hereinafter andwithout departing from the spirit of the present disclosure, variousfeatures of different embodiments can be replaced, rearranged, orcombined to accomplish other embodiments.

Referring to FIG. 1 , FIG. 1 is a partial schematic diagram of theelement arrangement of an electronic device of the present disclosure.As shown in FIG. 1 , the present disclosure electronic device EDincludes an X-ray detection device 100, wherein the X-ray detectiondevice 100 may include a detection array composed of a plurality ofsensing pixels, and FIG. 1 shows the arrangement of one sensing pixelPX. On sensing pixel PX may include one switch element SW and one sensorSER. The sensor SER is electrically connected to the switch element SW,and, for example, the switch element SW may be a transistor, such as athin film transistor (TFT), including a gate, a drain, and a source,whose gate and drain may be electrically connected to a gate line GL anda signal line SL respectively. It should be noted that one singlesensing pixel PX is not limited to including only one transistor. Forexample, one single sensing pixel PX may include two or threetransistors, but the present disclosure is noted limited thereto.According to the present disclosure, the electronic device ED includingthe X-ray detection device 100 shown in FIG. 1 may be a medical X-raycamera as an example, but not limited thereto. In a variant embodiment,the electronic device ED may be a detector used for detecting thequality of products for instance. The sensor SER may be a photodiode asan example, but not limited thereto.

Referring to FIG. 2 , FIG. 2 is a partial cross-sectional schematicdiagram of an X-ray detection device according to a first embodiment ofthe present disclosure. The present disclosure X-ray detection device100 may be applied to an electronic device ED, and the partial elementof the X-ray detection device 100 shown in FIG. 2 may correspond to onesensing pixel PX shown in FIG. 1 for example, but not limited thereto.In addition, each of the partial elements of the X-ray detection devicesof other embodiments of the present disclosure shown in FIG. 3 to FIG.9(A) may be considered as corresponding to one sensing pixel PXrespectively, which will not be repeatedly described. The presentdisclosure X-ray detection device 100 includes a substrate 102 andincludes a first transistor T1, a second transistor T2, a sensor SER, ascintillator SCI, a first barrier layer BL1, and a second barrier layerBL2 disposed on the substrate 102. The substrate 102 may for exampleinclude a rigid substrate, a flexible substrate, or a combination of theabove-mentioned substrates, but not limited thereto. The material of therigid substrate may for example include glass, ceramics, quartz,sapphire, or a combination of the materials mentioned above. Thematerial of the flexible substrate may for example include polyimide(PI), polycarbonate (PC), polyethylene terephthalate (PET), othersuitable material (s), or a combination of the materials mentionedabove. It should be noted that although the substrate 102 shown in FIG.2 is a single-layered structure, this embodiment is not limited thereto.In some embodiments, the substrate 102 may include a multi-layeredstructure, such as including a stacked structure formed oforganic-layer/inorganic-layer/organic-layer. The first transistor T1 andthe second transistor T2 include a gate (GE), a channel region (CH), asource region (SR), and a drain region (DR) respectively, wherein thesource region SR and the drain region DR may serve as the source and thedrain of the transistor respectively. The channel region CH, the sourceregion SR, and the drain region DR may be formed by a semiconductorlayer. The channel region CH is overlapped with the gate GE. In anembodiment, a conductive layer may be electrically connected to thesource region SR and the drain region DR to form a source electrode (SE)and a drain electrode (DE) through two via holes respectively. Thesemiconductor layer may include silicon semiconductor, metal oxidesemiconductor, other suitable materials, or a combination of thematerials mentioned above, but the present disclosure is not limitedthereto. Silicon semiconductor may include amorphous siliconsemiconductor, single crystalline silicon semiconductor, poly-siliconsemiconductor, or other suitable materials, and the present disclosureis not limited thereto. Metal oxide semiconductor includes indiumgallium zinc oxide (IGZO) semiconductor or other suitable material(s),and the present disclosure is not limited thereto. In this embodiment,the semiconductor layer of the first transistor T1 may for example be asilicon semiconductor SM1 (such as a low-temperature polysilicon (LTPS)semiconductor layer), the semiconductor layer of the second transistorT2 may for example be a metal oxide semiconductor SM2 (such as anindium-gallium-zinc oxide semiconductor layer), and the presentdisclosure is not limited thereto. Wherein, the transistors may includebottom-gate type transistors, top-gate type transistors, double-gatetype transistors, or a combination of the above-mentioned transistors,but the present disclosure is not limited thereto. In addition, when thetransistors include different semiconductor layers, their sources anddrains may be exchanged, and the present disclosure is not limitedthereto. In the embodiment shown in FIG. 2 , the silicon semiconductorSM1 is disposed between the metal oxide semiconductor SM2 and thesubstrate 102, the gate GE1 of the first transistor T1 is disposedbetween the gate GE2 of the second transistor T2 and the substrate 102,and the gate GE1 and the gate GE2 are formed by a first conductive layerML1 and a second conductive layer ML2 respectively. The source regionSR1 and the drain region DR1 of the first transistor T1 are disposed attwo sides of the channel region CH1 and electrically connected to asource electrode SE1 and a drain electrode DE1 respectively, the sourceregion SR2 and the drain region DR2 of the second transistor T2 aredisposed at two sides of the channel region CH2 and electricallyconnected to a source electrode SE2 and a drain electrode DE2respectively, and the source electrode SE1, the source electrode SE2,the drain electrode DE1, and the drain electrode DE2 may be formed by asame third conductive layer ML3, but not limited thereto. In a variantembodiment, for example, the source electrode SE1, the source electrodeSE2, the drain electrode DE1, and the drain electrode DE2 may be formedby more than one conductive layer, or the gate GE1 and the gate GE2 maybe formed by a same conductive layer. The first conductive layer ML1,the second conductive layer ML2, and the third conductive layer ML3 mayinclude metal material (s) and may be a metal layer respectively, butnot limited thereto. The source electrode SE1 and the drain electrodeDE1 may penetrate through the first gate insulating layer GI1, the firstinsulating layer 104, the first barrier layer BL1, the second gateinsulating layer GI2, and the second insulating layer 106, so as toconnect with the source region SR1 and the drain region DR1 of thesilicon semiconductor SM1. The source electrode SE2 and the drainelectrode DE2 may penetrate through the second insulating layer 106 andthe second gate insulating layer GI2, so as to connect with the sourceregion SR2 and the drain region DR2 of the metal oxide semiconductorSM2, and a portion of the drain electrode DE2 may further penetratethrough the first barrier layer BL1 and the first insulating layer 104to connect with a connection element 108 and be electrically connectedto the gate GE1 of the first transistor T1 through the connectionelement 108. The connection element 108 and the gate GE1 may be formedby the same first conductive layer ML1. In some embodiments, theconnection element 108 may be connected to the gate GE1 directly, butnot limited thereto. In FIG. 2 , the first transistor T1 and the secondtransistor T2 may not be overlapped with each other in a first directionD1 that is in parallel with the normal direction of the surface of thesubstrate 102, which also means that the first transistor T1 and thesecond transistor T2 may be arranged side by side along a seconddirection D2 that is perpendicular to the first direction D1 of thenormal line of the substrate 102. However, the relative arrangementpositions between each component of the first transistor T1 and thesecond transistor T2 and between the two transistors of the presentdisclosure are not limited to the above-described structure. Forexample, in a variant embodiment, the first transistor T1 and the secondtransistor T2 may be at least partially overlapped in the firstdirection D1.

For example, the materials of the first gate insulating layer GI1, thefirst insulating layer 104, the second gate insulating layer GI2, andthe second insulating layer 106 may include silicon oxide, but notlimited thereto, and any suitable insulating material may be applied tothe above-mentioned insulating layers. In a variant embodiment, thefirst insulating layer 104 may include silicon nitride with theadvantage that silicon nitride includes hydrogen ions therein, whereinhydrogen ions are capable of diffusing into the silicon semiconductorSM1, which can improve the electrical performance of the firsttransistor T1.

The sensor SER is disposed on the first transistor T1 and the secondtransistor T2, and the sensor SER is electrically connected to the firsttransistor T1 and the second transistor T2. It should be noted that thesensor SER shown in FIG. 2 is not overlapped with the first transistorT1 or the second transistor T2 in the sectional view or in the firstdirection D1 of the substrate 102, but the structure of the presentdisclosure is not limited to the illustrated structure of FIG. 2 . Thedescription of “the sensor SER is disposed on the first transistor T1and the second transistor T2” may include the situation that the sensorSER is at least partially overlapped with the first transistor T1 or thesecond transistor T2 or the situation that the sensor SER is notoverlapped with the first transistor T1 nor the second transistor T2. Inaddition, the sensor SER for example may include a P-intrinsic-N (PIN)photodiode 110, such as an amorphous silicon photodiode, a polysiliconphotodiode, a single crystalline silicon photodiode, or other suitablesensors, but not limited thereto. The PIN photodiode 110 may include anN-type semiconductor layer 110 a, an intrinsic layer 110 b, and a P-typesemiconductor layer 110 c, the bottom electrode 112 of the sensor SER isdisposed at the lower side of the PIN photodiode 110, and the bottomelectrode 112 may be electrically connected to the drain electrode DE2of the second transistor T2 through the connection element 116, as shownin FIG. 2 . The bottom electrode 112 and the connection element 116 maybe formed by the same fourth conductive layer ML4, but the presentdisclosure is not limited thereto. For example, the bottom electrode 112may be electrically connected to the second transistor T2 by other wayor with other structure. The top electrode 114 of the sensor SER isdisposed at the upper side of the PIN photodiode 110 and may beelectrically connected to a connection element 118. The X-ray detectiondevice 100 may selectively include a planarization layer 120 that coversthe sensor SER, wherein a portion of the connection element 118 may bedisposed on the planarization layer 120, and another portion of theconnection element 118 may penetrate into a portion of the planarizationlayer 120 to electrically connect with the top electrode 114 of thesensor SER, but not limited thereto. The material of the planarizationlayer 120 may include acrylic-based polymer, siloxane-based polymer,epoxy-based polymer, other suitable materials, or a combination of thematerials mentioned above, but the present disclosure is not limitedthereto. The scintillator SCI is disposed on the sensor SER, such asbeing disposed on the planarization layer 120. The scintillator SCI iscapable of transforming the X-ray that enters the X-ray detection device100 into visible light or other kinds of light that can enable thesensor SER to produce photocurrent. As shown in FIG. 2 , thescintillator SCI can transform X-ray into visible light, wherein thelight LT representing the X-ray may enter the scintillator SCI from thefront surface SCIa of the scintillator SCI, then be transformed into thelight LT′ representing visible light by the scintillator SCI, and thesensor SER is capable of receiving at least a part of the light LT′. Thescintillator SCI may include microcoluminar thallium doped caesiumiodide (CsI:Tl) for example, but not limited thereto. In addition, otherlayer(s) may be disposed between the scintillator SCI and the sensorSER, such as an insulating layer, a dielectric layer, and/or a metalthin-film, but the present disclosure is not limited thereto. In avariant embodiment, the X-ray detection device 100 may not include thescintillator SCI and the sensor SER may receive the light that entersfrom the exterior directly. The structures and relative disposition ofthe sensor SER and the scintillator SCI of the present disclosure arenot limited to the above description and may be applied to otherembodiments of the present disclosure, which will not be repeatedlydescribed.

Furthermore, as shown in FIG. 2 , the first barrier layer BL1 isdisposed between the first transistor T1 and the second transistor T2,and the second barrier layer BL2 is disposed between the secondtransistor T2 and the sensor SER, wherein the first transistor T1 andthe second transistor T2 may be or not be overlapped with each other inthe first direction D1. The first barrier layer BL1 and the secondbarrier layer BL2 include insulating materials. For example, the firstbarrier layer BL1 may include silicon oxide (SiOx), and the secondbarrier layer BL2 may include silicon oxide, silicon nitride (SiNx),silicon oxynitride, or a combination thereof, but not limited thereto.It should be noted that the first barrier layer BL1 and the secondbarrier layer BL2 are different from each other by at least one of theparameters including film material, density, thickness, processcondition (such as process temperature), hydrogen concentration, andetc. By the variation design of these parameters, the present disclosureenables the first barrier layer BL1 and the second barrier layer BL2 tohave different properties, so as to improve the sensing performance ofthe X-ray detection device 100. The parameter ranges and design reasonsof the first barrier layer BL1 and the second barrier layer BL2 will bedescribed in detail below.

According to the present disclosure, since the first transistor T1includes the silicon semiconductor SM1, the hydrogen ions of the firstinsulating layer 104 are capable of differing to the siliconsemiconductor SM1 when the first insulating layer 104 has a higherhydrogen concentration, which can improve the property of the siliconsemiconductor SM1. For example, the first insulating layer 104 mayinclude silicon nitride or silicon oxide with higher hydrogenconcentration. In another aspect, in order to mitigate the hydrogen ionsof the first insulating layer 104 from differing into the metal oxidesemiconductor SM2 of the second transistor T1 to influence itssemiconductor property, the first barrier layer BL1 is designed to bedisposed between the first transistor T1 and the second transistor T2according to the present disclosure. For example, the first barrierlayer BL1 may be disposed between the silicon semiconductor SM1 and themetal oxide semiconductor SM2, or disposed between the first insulatinglayer 104 and the metal oxide semiconductor SM2 (or the secondtransistor T2), so as to mitigate the situation that the hydrogen ionsof the first insulating layer 104 differ into the metal oxidesemiconductor SM2. As a result, the first barrier layer BL1 should havethe properties of a lower hydrogen concentration and a higher filmdensity in comparison with the first insulating layer 104. For example,the first barrier layer BL1 may have a higher process temperature withthe range from 300° C. to 360° C., a hydrogen concentration with theweight percentage range from 2% to 5%, such as 2%, 2.5%, 3%, 4%, or 5%,and a thickness range from about 80 nanometers (nm) to about 200 nm,such as 80 nm, 120 nm, or 150 nm, but the film parameters of the firstbarrier layer BL1 are not limited to the above description.

In another aspect, silane (SiH4) gas will be introduced during thefabrication process of the sensor SER. In order to mitigate theinfluence on the metal oxide semiconductor SM2, the second barrier layerBL2 of the present disclosure also has a certain parameter condition.For example, compared with the first barrier layer BL1, the secondbarrier layer BL2 should have the properties of a lower processtemperature, a lower density, and/or a higher hydrogen concentration. Inother words, the hydrogen concentration of the second barrier layer BL2is greater than the hydrogen concentration of the first barrier layerBL1, the density of the first barrier layer BL1 is greater than thedensity of the second barrier layer BL2, and the thickness of the firstbarrier layer BL1 is less than the thickness of the second barrier layerBL2. As an example, the range of the process temperature of the secondbarrier layer BL2 is from about 180° C. to about 240° C., the density ofthe second barrier layer BL2 is lower than the density of the firstbarrier layer BL1 by about 0.1-1.0 g/cm³, the range of the hydrogenconcentration of the second barrier layer BL2 is from about 5% to about11%, such as 5%, 6%, 7%, 8%, 9%, 10%, or 11%, and the range of the filmthickness of the second barrier layer BL2 is from about 200 nm to about500 nm, such as 200 nm, 250 nm, 300 nm, 400 nm, or 500 nm, but eachparameter of the second barrier layer BL2 of the present disclosure isnot limited to the above-mentioned examples.

The above-mentioned film thicknesses may be measured through X-rayreflection (XRR) method or by a transmission electron microscopy (TEM),but the present disclosure is not limited thereto. X-ray reflectionmethod may be carried out by using a high resolution X-ray diffractionanalyzer (HRXRD) to measure the target, such as (but not limited to)using Bruker Discover tool, which can measure the thickness, interfaceroughness, and electron density of the multi-layer/single-layer filmsamples by using the characteristic of total reflection of X-ray. Forexample, when measuring the density of the film, the thickness of thesample may be 300 nm or less, and in the case of the sample being in across section, the density of the film can be obtained by taking a pointfrom the middle of the film to measure. The above-mentioned thicknessmay also be measured by TEM. For example, the thickness of the film maybe directly measured from the TEM section photography diagram. Themeasuring point may be determined from any position of the barrier layercorresponding to the semiconductor layer. The measurement of theabove-mentioned hydrogen concentration of the film may be carried outfor example by using an X-ray photoelectron spectroscopy (XPS) or anelectron spectroscopy for chemical analysis (ESCA), or through Time ofFlight—the secondary ion mass spectrometry (TOF-SIMS) method or hydrogenforward scattering (HFS) method. The TOF-SIMS method may for exampleadopt (but not limited to) a nanoTOF II tool, wherein bismuth (Bi³⁺) ionbeam can be provided, and then the generated secondary ions, resultedfrom the ion beam, of the sample can be analyzed and measured. In theHFS method, the tool of ERDA is exemplified (but not limited thereto),such as providing a helium (He⁺⁺) ion beam to the film, and thenanalyzing and measuring the diffusing hydrogen ions or helium ions ofthe sample generated by the bombardment of the ion beam. In the XPS/ESCAanalyzing method, the tool of ESCALAB Xi+ is exemplified (but notlimited thereto), wherein the X-ray is enabled to enter the samplesurface, and the escaping electron energy from the sample surface iscaptured, so as to calculate the hydrogen concentration. The measurementmethods of the density, the thickness, and the hydrogen concentration offilms of the present disclosure are not limited to the abovedescription.

In addition, the present disclosure X-ray detection device 100 mayfurther include an insulating layer 122 disposed between the substrate102 and the first transistor T1. The hydrogen concentration of theinsulating layer 122 may be greater than the hydrogen concentration ofthe second barrier layer BL2, and may also be greater than the hydrogenconcentration of the first barrier layer BL1. The density of theinsulating layer 122 may be less than the density of the first barrierlayer BL1. The insulating layer 122 may serve as a buffer layer, andwhen fabricating the silicon semiconductor layer SM1, the continuousdiffusion of moisture or oxygen permeating through the substrate 102 canbe reduced, thereby reducing the effect of the moisture or oxygen on theproperties of the transistors. The insulating layer 122 may be asingle-layered structure or a multi-layered structure, and is notlimited to the one layer structure shown in FIG. 2 . When the insulatinglayer 122 is a single-layered structure, the material of the insulatinglayer 122 may for example include silicon oxide, silicon nitride,silicon oxynitride, or a combination thereof, but not limited thereto.When the insulating layer 122 is a multi-layered structure, differentmaterials may be stacked alternately, but the present disclosure is notlimited thereto.

According to the present disclosure, the disposition of the firstbarrier layer BL1 is capable of mitigating the situation that thehydrogen ions in the films therebelow diffuse into the metal oxidesemiconductor SM2, thus its undesired effect on the metal oxidesemiconductor SM2 may be reduced. The disposition of the second barrierlayer BL2 is also capable of mitigating the problem that the hydrogenions diffuse into the metal oxide semiconductor SM2 when fabricating thesensor SER. Therefore, when the first barrier layer BL1 and the secondbarrier layer BL2 are disposed, the electrical performance of differenttransistors may be improved. In another aspect, the present disclosureX-ray detection device 100 includes transistors having semiconductorswith different materials, thus they may be used as different electricelements of the sensing pixel PX based on their property orcharacteristic respectively, so as to increase the sensing effect of thesensing pixel.

It should be noted that FIG. 2 only exemplarily shows thecross-sectional structure of the partial elements of the firstembodiment of the X-ray detection device of the present disclosure, andthe X-ray detection device of the present disclosure is not limited toFIG. 2 . Other embodiments and variant embodiments of the X-raydetection device of the present disclosure will be introduced in thefollowing. In order to simplify the description, the same films orelements in the following embodiments will be marked with the samelabels and their features will not be repeated, and the differencesbetween the embodiments will be described in detail below.

Referring to FIG. 3 , FIG. 3 is a partial cross-sectional schematicdiagram of an X-ray detection device according to a second embodiment ofthe present disclosure. This embodiment and the first embodiment isdifferent in that the X-ray detection device 100 in FIG. 3 includes twoinsulating layers disposed between the silicon semiconductor SM1 and themetal oxide semiconductor SM2 and includes two buffer layers disposedbetween the substrate 102 and the silicon semiconductor SM1. As shown inFIG. 3 , the first insulating layer 104 and the third insulating layer105 are disposed on the silicon semiconductor SM1 in order, which canserve as the interlayer dielectric layers. The source electrode SE1 andthe drain electrode DE1 formed by the third conductive layer ML3 maypenetrate through the first insulating layer 104 and the thirdinsulating layer 105. As an example, the material of the firstinsulating layer 104 may include silicon oxide, and the material of thethird insulating layer 105 may include silicon nitride, but not limitedthereto. The materials of the first insulating layer 104 and the thirdinsulating layer 105 may be exchanged. When the first insulating layer104 or the third insulating layer 105 includes silicon nitride, itshydrogen ions may diffuse downward into the silicon semiconductor SM1 toimprove the electrical performance of the first transistor T1. Inaddition, the insulating layer 122 and the insulating layer 124 aredisposed between the first transistor T1 and the substrate 102, whichmay provide the buffering function to reduce the moisture and/or oxygenpermeating from the lower side of the substrate 102. The materials ofthe insulating layer 122 and the insulating layer 124 may for exampleinclude silicon oxide, silicon nitride, silicon oxynitride, or acombination thereof, but not limited thereto. The insulating layer 122and the insulating layer 124 may include different materials. Forexample, the insulating layer 122 may include silicon nitride and theinsulating layer 124 may include silicon oxide, but not limited thereto.The hydrogen concentration of the insulating layer 124 may be greaterthan the hydrogen concentration of the second barrier layer BL2. Thedispositions and materials of the first insulating layer 104, the thirdinsulating layer 105, the insulating layer 122, and the insulating layer124 of this embodiment may be applied to other embodiments, which willnot be repeatedly described. Furthermore, at the upper side of thesensor SER, the scintillator SCI (not shown) may be omitted in the X-raydetection device 100 shown in FIG. 3 , and the light LT may enter thesensor SER from an upper surface 120 a of the planarization layer 120,wherein the light LT may be a visible light or any kind of light that iscapable of enabling the sensor SER to produce photocurrent. It should benotated that a variant embodiment of this embodiment may still include ascintillator SCI disposed at the upper side of the sensor SER and/or aninsulating layer disposed between the scintillator SCI and the sensorSER. The above-mentioned scintillator SCI and the insulating layerdisposed between the scintillator SCI and the sensor SER may be appliedto other following embodiments of the present disclosure, whosefunctions and materials may refer to the first embodiment and will notbe repeated.

Referring to FIG. 4 , FIG. 4 is a partial cross-sectional schematicdiagram of an X-ray detection device according to a third embodiment ofthe present disclosure. In comparison with the embodiment shown in FIG.3 , the X-ray detection device 100 shown in FIG. 4 further includes aplanarization layer 121 disposed between the sensor SER and the secondbarrier layer BL2. The disposition of the planarization layer 121 mayprovide a planar surface, which may improve the fabrication processand/or property of the sensor SER. Furthermore, although the insulatinglayers and barrier layers shown in FIG. 4 have flat upper surfaces andlower surfaces, in fact, these insulating layers or barrier layers mayfollow the pattern of the patterned layers or electric elements on theirlower side conformally, and therefore they may undulate to have unevenupper surfaces. The planarization layer 121 disposed on the secondbarrier layer BL2 in this embodiment is capable of providing a flatterupper surface, such that the sensor SER may be disposed on a flattersurface. The planarization layer 121 may include the material(s) aspreviously mentioned for the planarization layer 120, and the materialof the planarization layer 121 may be the same as or different from theplanarization layer 120.

Referring to FIG. 5 , FIG. 5 is a partial cross-sectional schematicdiagram of an X-ray detection device according to a fourth embodiment ofthe present disclosure. In comparison with FIG. 2 and FIG. 3 , the X-raydetection device 100 shown in FIG. 5 includes an insulating layer 126disposed between the insulating layer 122 and the silicon semiconductorSM1, and the material of the insulating layer 126 may for exampleinclude silicon nitride, silicon oxide, silicon oxynitride, or acombination thereof, but not limited thereto. The insulating layer 126is capable of reducing moisture and/or oxygen permeating from the lowerside (i.e., the backside) of the X-ray detection device 100 or thesubstrate 102, thereby reducing the damage to the elements caused bymoisture and/or oxygen. According to this embodiment, the hydrogenconcentration of the insulating layer 126 is greater than the hydrogenconcentration of the first barrier layer BL1, the density of theinsulating layer 126 is less than the density of the first barrier layerBL1. When the hydrogen concentration of the insulating layer 126 isgreater than the hydrogen concentration of the first barrier layer BL1and the density of the insulating layer 126 is less than the density ofthe first barrier layer BL1, the moisture and/or oxygen permeating fromthe substrate 102 can be reduced, and the tact time can be reduced, soas to reduce fabrication cost. The insulating layer 126 in thisembodiment may be applied to other embodiments of the presentdisclosure, which will not be repeatedly described. Furthermore, theX-ray detection device 100 shown in FIG. 5 may further include aninsulating layer 128 disposed on the sensor SER, and the insulatinglayer 128 may include silicon nitride, silicon oxide, siliconoxynitride, or a combination thereof, but not limited thereto. Theinsulating layer 128 may serve as a third barrier layer to mitigate thepermeation of moisture and/or oxygen from exterior, which means themoisture and/or oxygen permeating from the exterior of the X-raydetection device 100 (such as from the upper side of the X-ray detectiondevice 100) can be reduced. According to this embodiment, when thehydrogen concentration of the insulating layer 128 is less than thehydrogen concentration of the second barrier layer BL2 and the densityof the insulating layer 128 is greater than the density of the secondbarrier layer BL2, the insulating layer 128 is capable of reducing thepermeation of moisture and/or oxygen. The insulating layer 128 in thisembodiment may be applied to other embodiments of the presentdisclosure, which will not be repeatedly described.

Referring to FIG. 6 , FIG. 6 is a partial cross-sectional schematicdiagram of an X-ray detection device according to a fifth embodiment ofthe present disclosure. In comparison with the embodiment shown in FIG.3 , the X-ray detection device 100 shown in FIG. 6 further includes alight-shielding element 130 disposed between the planarization layer 120and the second barrier layer BL2. For example, the light-shieldingelement 130 may be at least partially overlapped with the firsttransistor T1 or entirely overlap with the first transistor T1 in thefirst direction D1, which is capable of reducing light entering thefirst transistor T1 from the upper side of the X-ray detection device100, so as to improve the electrical performance of the first transistorT1. The light-shielding element 130 and the bottom electrode 112 of thesensor SER may be formed by the same fourth conductive layer ML4, whichmeans the light-shielding element 130 and the bottom electrode 112 ofthe sensor SER may be formed together by a same patterning process, butthe present disclosure is not limited thereto. In FIG. 6 , thelight-shielding element 130 may be electrically connected to theconnection element 116 directly, but the present disclosure is notlimited thereto. In a variant embodiment, the light-shielding element130 may not be electrically connected to the connection element 116,such as (but not limited to) that the light-shielding element 130 isfloating. Since the fourth conductive layer ML4 has a farther distancefrom the first transistor T1, when the fourth conductive layer ML4 isused to form the light-shielding element 130, the coupling effectbetween the light-shielding element 130 and the first transistor T1 isless, thus the induced coupling capacitance is smaller and will lesslikely affect the property of the first transistor T1. Thelight-shielding element 130 of this embodiment may be applied to otherembodiments of the present disclosure, which will not be repeatedlydescribed.

Referring to FIG. 7 , FIG. 7 is a partial cross-sectional schematicdiagram of an X-ray detection device according to a sixth embodiment ofthe present disclosure. In comparison with the embodiment shown in FIG.4 , the X-ray detection device 100 shown in FIG. 7 further includes alight-shielding layer ML5 disposed between the planarization layer 121and the second barrier layer BL2, wherein the patterned light-shieldinglayer ML5 may include a light-shielding element 131 and alight-shielding element 132 at least partially overlapped with thesecond transistor T2 and the first transistor T1 in the first directionD1 respectively. As an example, the light-shielding element 131 may beat least partially overlapped with metal oxide semiconductor SM2 in thefirst direction D1, and the light-shielding element 132 may be at leastpartially overlapped with the silicon semiconductor SM1 in the firstdirection D1. The light-shielding element 131 and the light-shieldingelement 132 may reduce or decrease the light entering from the upperside of the X-ray detection device 100, so as to lower the influence onthe second transistor T2 and the first transistor T1 by light exposure.The light-shielding layer ML5 may include a conductive material, such asa metal layer, and at this time, the light-shielding element 131 and thelight-shielding element 132 may be in a floating state without beingelectrically connected to other elements. The light-shielding layer ML5may also include insulating material, such as polymer material ororganic material including black pigment. In some embodiments, thelight-shielding layer ML5 may be, for example, a black matrix layer. Thematerial of the light-shielding layer ML5 is not limited to the above.The light-shielding layer ML5 in this embodiment may be applied to otherembodiments of the present disclosure, which will not be repeatedlydescribed.

Referring to FIG. 8 , FIG. 8 is a partial cross-sectional schematicdiagram of an X-ray detection device according to a seventh embodimentof the present disclosure. Compared with the structure shown in FIG. 6 ,the X-ray detection device 100 of FIG. 8 includes a capacitor electrode136 disposed at the lower side of the bottom electrode 112 of the sensorSER, and the second barrier layer BL2 is disposed between the bottomelectrode 112 and the capacitor electrode 136. As a result, thecapacitor electrode 136, the bottom electrode 112, and the secondbarrier layer BL2 between the capacitor electrode 136 and the bottomelectrode 112 may form a capacitor together. The capacitor electrode 136in this embodiment may be formed by the third conductive layer ML3. Thecapacitor electrode 136 may be formed together when forming the sourceelectrode SE1, the source electrode SE2, the drain electrode DE1, andthe drain electrode DE2, but not limited thereto. The capacitorelectrode 136 may be applied to other embodiments of the presentdisclosure, which will not be repeatedly described.

Referring to FIG. 9(A) and FIG. 9(B), FIG. 9(A) is a partialcross-sectional diagram of an X-ray detection device according to aneighth embodiment of the present disclosure, and FIG. 9(B) is anequivalent circuit diagram of one sensing pixel PX of the X-raydetection device shown in FIG. 9(A). The third transistor T3 includes agate GE3, a channel region CH3, a source region SR3, and a drain regionDR3. The source region SR3 and the drain region DR3 may be the sourceand drain of the third transistor T3 respectively. The channel regionCH3, the source region SR3, and the drain region DR3 may be formed by asemiconductor SM3, wherein the channel region CH3 is overlapped with thegate GE3. For example, in the embodiment shown in FIG. 9(A), a portionof the third conductive layer ML3 may be electrically connected to thesource region SR3 and the drain region DR3 through two via holes to formthe source electrode SE3 and the drain electrode DE3 respectively. Inother words, the source electrode SE3 and the drain electrode DE3penetrate through the second gate insulating layer GI2 and the secondinsulating layer 106 to connect with the source region SR3 and the drainregion DR3 of the semiconductor SM3. The semiconductor SM3 of the thirdtransistor T3 may include silicon semiconductor, metal oxidesemiconductor, other suitable materials, or a combination of thematerials mentioned above, but the present disclosure is not limitedthereto. The silicon semiconductor and metal oxide semiconductor of thematerial of the semiconductor SM3 may refer to the above descriptions ofthe first transistor T1 and the second transistor T2, for instance, andwill not be repeated. As an example, the semiconductor SM3 of the thirdtransistor T3 in this embodiment is a metal oxide semiconductor, but notlimited thereto. The third transistor T3 may include a bottom-gate typetransistor, a top-gate type transistors, a double-gate type transistor,or a combination of the above-mentioned transistors, and the presentdisclosure is not limited thereto. The gate GE3 of the third transistorT3 and the gate GE2 of the second transistor T2 may both be formed bythe second conductive layer ML2, and the semiconductor layers of thethird transistor T3 and the second transistor T2 (i.e., thesemiconductor SM3 and the metal oxide semiconductor SM2) may be formedby the same process steps. The source electrode SE3 and drain electrodeDE3 corresponding to the third transistor T3 and the source electrodeSE2 and drain electrode DE2 corresponding to the second transistor T2 orthe source electrode SE1 and drain electrode DE1 corresponding to thefirst transistor T1 may be formed by the same third conductive layerML3, but not limited thereto. The source electrode SE3 may beelectrically connected to the drain electrode DE1 directly, but notlimited thereto. Furthermore, the first conductive layer ML1 may furtherselectively include a gate 140 disposed between the gate GE3 and thesubstrate 102, and the gate 140 may be electrically connected to thegate GE3. Both of the gate 140 and gate GE3 may serve as the gate of thethird transistor T3. For example, the gate 140 may be the lower gateelectrode, the gate GE3 may be the upper gate electrode, and one of thegate 140 and the gate GE3 may be electrically connected to the controlline to switch on/off the third transistor T3. The gate 140 in thisembodiment may be formed by the first conductive layer ML1 together withthe gate GE1, and when the gate 140 includes an opaque material, it mayalso be used as a light-shielding element to reduce or lower theincident light from the lower side of the substrate 102, reducing theinfluence of light on the semiconductor SM3. However, the arrangementposition of the gate 140 and its formation film of the presentdisclosure are not limited to those shown in FIG. 9(A). In a variantembodiment, the gate 140 may be, for example, disposed between the firstbarrier layer BL1 and the third insulating layer 105 or disposed betweenthe third insulating layer 105 and the first insulating layer 104, andformed by other conductive layers, but the present disclosure is notlimited to the above.

The equivalent circuit 150 of one sensing pixel PX shown in FIG. 9(B)substantially corresponds to the elements shown in FIG. 9(A), whereinthe second transistor T2 may serve as a reset element in the sensingpixel PX, its source may be supplied with a reset voltage Vres, and itsdrain and the bottom electrode of the sensor SER are electricallyconnected to the gate of the first transistor T1. The first transistorT1 may serve as an amplifying element in the sensing pixel PX, used asan amplifier, its source may be provided with a common voltage Vcom or aworking voltage, and the drain of the first transistor T1 may beelectrically connected to the source of the third transistor T3. Thethird transistor T3 may serve as a readout element in the sensing pixelPX, wherein the drain of the third transistor T3 may be electricallyconnected to a signal readout line 152 or a signal readout unit (notshown), and the signal readout line 152 is capable of outputting theoutput signal amplified by the first transistor T1, that is, the outputcurrent Id for the signal reading unit to perform signal analysis.

According to the present disclosure, the second transistor T2 serving asthe reset element may include a metal oxide semiconductor, which has theadvantages of low leakage and/or accurate zeroing, thus improving thedetection accuracy of the sensing pixel PX to the light intensity, suchas the metal oxide semiconductor SM2 shown in FIG. 9(A). In anotheraspect, the first transistor T1 may include a silicon semiconductor, andthe third transistor T3 may include a metal oxide semiconductor or asilicon semiconductor. In the structure shown in FIG. 9(A), the activelayer of the first transistor T1 is, for example, a siliconsemiconductor SM1. Since the electron mobility of the siliconsemiconductor SM1 is higher, the signal-to-noise ratio may be raised,thereby improving detection sensitivity of light; and the active layer(i.e., the semiconductor SM3) of the third transistor T3 is, forexample, a metal oxide semiconductor, which is capable of forming atransistor with low leakage current and is capable of reducing the errorrate of reading signals.

Referring to FIG. 10 , FIG. 10 is a schematic diagram of process flow ofthe fabrication of the X-ray detection device according to the presentdisclosure. According to the present disclosure, the fabrication methodof the X-ray detection device 100 may substantially include thefollowing steps:

Step 502: Provide a substrate. For example, the substrate 102 isprovided as mentioned in the foregoing embodiments.

Step 504: Form a semiconductor layer. For example, a patterned siliconsemiconductor SM1 is formed on the substrate 102, wherein the pattern ofthe silicon semiconductor SM1 may correspond at least to the activeregion of the first transistor T1 to be fabricated.

Step 506: Forma first barrier layer on the semiconductor layer. Forexample, the first barrier layer BL1 is formed on the siliconsemiconductor SM1, wherein before the formation of the first barrierlayer BL1, the first gate insulating layer GI1, the patterned firstconductive layer ML1, and the first insulating layer 104 may be formedon the silicon semiconductor SM1, but not limited thereto.

Step 508: Form a semiconductor layer on the substrate. For example,after forming the first barrier layer BL1, the patterned metal oxidesemiconductor SM2 is formed on the substrate 102, wherein the pattern ofthe metal oxide semiconductor SM2 may correspond to at least the activeregion of the second transistor T2 to be fabricated. In someembodiments, the metal oxide semiconductor SM2 in this step may beformed on the first barrier layer BL1 formed in Step 506, but notlimited thereto.

Step 510: Form a second barrier layer on the semiconductor layer formedin Step 508. For example, the second barrier layer BL2 is formed on themetal oxide semiconductor SM2, wherein before the formation of thesecond barrier layer BL2, the second gate insulating layer GI2, thepatterned second conductive layer ML2, the patterned second insulatinglayer 106, and the patterned third conductive layer ML3 may be formed onthe metal oxide semiconductor SM2, but not limited thereto.

Step 512: Form a sensor. For example, the sensor SER is formed on thesecond transistor T2, and the sensor SER may include a photodiode, butnot limited thereto.

In the above steps, plasma enhanced chemical vapor deposition (PECVD)process, plasma enhanced atomic layer deposition (PEALD) process, ormetal organic atomic layer deposition (MOALD) process may be used toform the first barrier layer and the second barrier layer. SiH4 gas maybe introduced during the process, and a radio frequency (RF) powergenerator may be used as a plasma source. In some embodiments, a firstSiH4 parameter in the first barrier layer process may be smaller than asecond SiH4 parameter in the second barrier layer process. Theabove-mentioned SiH4 parameter includes, for example, the gas flow rateper unit time of SiH4, wherein when the gas flow rate per unit time ofSiH4 is higher, the hydrogen concentration of the formed film becomeshigher. For example, the flow rate of SiH4 of the first barrier layerranges from 200 to 800 standard cubic centimeters per minute (sccm),such as 200 sccm, 300 sccm, 400 sccm, 600 sccm, or 800 sccm; the flowrate of SiH4 of the second barrier layer ranges from 801 to 2400 sccm,such as 1000 sccm, 1200 sccm, 1600 sccm, or 2400 sccm, but the presentdisclosure is not limited to the above. In some embodiments, a first RFpower parameter in the first barrier layer process may be greater than asecond RF power parameter in the second barrier layer process, and theabove-mentioned RF power parameter is proportional to the plasmaintensity. When the plasma intensity is greater, the denseness of theformed film is higher, and the density of the formed film layer ishigher.

As can be seen from the above, the X-ray detection device of the presentdisclosure includes two transistors and a sensor, wherein the twotransistors may respectively include semiconductor layers of differentmaterials, for example, one is a silicon semiconductor, and the otherone is a metal oxide semiconductor. In addition, a barrier layer isdisposed between the two semiconductor layers of different materials,and another barrier layer may also be disposed between the sensor andthe transistors. By disposing the barrier layers and adjusting theprocess parameters and/or film parameters of the two barrier layers,protective functions may be provided to the semiconductor layers, or theelectrical performance of the semiconductor layers may be improved. Forexample, the diffusion of hydrogen ions into the metal oxidesemiconductor can be reduced, and/or the property of the siliconsemiconductor can be improved, thereby improving the electricalperformances of different transistors respectively. In another aspect,the transistors including different semiconductor materials may beselected as a reset element, an amplifying element, or a readoutelement, or other functional transistor in the sensing pixel based ontheir characteristics, so as to improve the sensing accuracy of thesensing pixel.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the disclosure. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. An X-ray detection device, comprising: asubstrate; a first transistor disposed on the substrate and comprising asilicon semiconductor; a second transistor disposed on the substrate andcomprising a metal oxide semiconductor; a sensor disposed on the firsttransistor and the second transistor and electrically connected to thefirst transistor and the second transistor; a scintillator disposed onthe sensor; a first barrier layer disposed between the first transistorand the second transistor; and a second barrier layer disposed betweenthe second transistor and the sensor.
 2. The X-ray detection device asclaimed in claim 1, wherein a hydrogen concentration of the secondbarrier layer is greater than a hydrogen concentration of the firstbarrier layer.
 3. The X-ray detection device as claimed in claim 2,further comprising an insulating layer disposed between the firsttransistor and the substrate, and a hydrogen concentration of theinsulating layer is greater than the hydrogen concentration of thesecond barrier layer.
 4. The X-ray detection device as claimed in claim1, wherein a density of the first barrier layer is greater than adensity of the second barrier layer.
 5. The X-ray detection device asclaimed in claim 1, wherein a thickness of the first barrier layer isless than a thickness of the second barrier layer.
 6. The X-raydetection device as claimed in claim 1, wherein a material of the firstbarrier layer comprises silicon oxide.
 7. The X-ray detection device asclaimed in claim 1, wherein a material of the second barrier layercomprises silicon oxide, silicon nitride, or a combination thereof. 8.The X-ray detection device as claimed in claim 1, wherein the sensor isa P-intrinsic-N (PIN) photodiode.